Question

Tìm x thuộc N biết 

A . (x-15)×15=0 

B 32(x-10)=32

C (x-5) (x-7)=0 

D(x-35) ×35=35

Answer 1

A.\(\left(x-15\right).15=0\)

\(x-15=0:15\)

\(x-15=0\)

\(x=15+0\)

\(x=15\)

B.\(32\left(x-10\right)=32\)

\(x-10=32:32\)

\(x-10=1\)

\(x=10+1\)

\(x=11\)

 

Answer 2

`a) `

`(x-15)xx15=0`

`<=> x-15 = 0 : 15`

`<=> x-15 = 0`

`<=> x = 0 + 15`

`<=> x =15`

`b)`

`32.(x-10)=32`

`<=> x - 10 = 32:32`

`<=>x-10=1`

`<=> x = 1+10`

`<=> x =11`

`c)`

`(x-5).(x-7)=0`

`<=>` \(\left[ \begin{array}{l}x-5 = 0\\x-7=0\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=5\\x=7\end{array} \right.\) 

`d)`

`(x-35)xx35=35`

`<=> x - 35 = 35:35`

`<=> x - 35 = 1`

`<=> x = 1+35`

`<=> x = 36`